Monoclonal antibody-based serological methods for detection of Cucumber green mottle mosaic virus

<p>Abstract</p> <p>Background</p> <p>Cucumber green mottle mosaic virus (CGMMV), a member of the genus <it>Tobamovirus</it>, can be transmitted by seeds and infects many cucurbit species, causing serious yield losses in cucumber and watermelon plants. In this paper, five serological methods including antigen-coated plate enzyme-linked immunosorbent assay (ACP-ELISA), triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA), Dot-immunobinding assay (DBIA), direct tissue blot immunoassay (DTBIA) and immunocapture reverse transcriptase polymerase chain reaction (IC-RT-PCR) were described for detection and diagnosis of CGMMV.</p> <p>Results</p> <p>Using the purified CGMMV particles as immunogens, six murine monoclonal antibodies (MAbs) were produced. Five serological methods were established using the MAb 4H1 and detection sensitivity was compared using purified preparations and infected-plant tissue extracts. The detection sensitivity of ACP-ELISA was 0.16 ng of purified CGMMV, whereas TAS-ELISA was more sensitive than ACP-ELISA with a minimum detection of 0.04 ng of purified CGMMV. The sensitivities of TAS-ELISA and DBIA were similar for detecting CGMMV in infected-plant tissue extracts, and were four times higher than ACP-ELISA. The IC-RT-PCR was the most sensitive method, which could detect as little as 0.1 pg of purified virus. The detection sensitivity of IC-RT-PCR for CGMMV-infected plant tissues was about 400 times higher than that of TAS-ELISA and DBIA.</p> <p>Conclusions</p> <p>The established ACP-ELISA, TAS-ELISA, DBIA and DTBIA are suitable for routine CGMMV detection of large-scale samples in the field survey, while IC-RT-PCR is more sensitive and suitable for acquiring information about the viral genome.</p

Grasp Stability Assessment Through Attention-Guided Cross-Modality Fusion and Transfer Learning

Extensive research has been conducted on assessing grasp stability, a crucial prerequisite for achieving optimal grasping strategies, including the minimum force grasping policy. However, existing works employ basic feature-level fusion techniques to combine visual and tactile modalities, resulting in the inadequate utilization of complementary information and the inability to model interactions between unimodal features. This work proposes an attention-guided cross-modality fusion architecture to comprehensively integrate visual and tactile features. This model mainly comprises convolutional neural networks (CNNs), self-attention, and cross-attention mechanisms. In addition, most existing methods collect datasets from real-world systems, which is time-consuming and high-cost, and the datasets collected are comparatively limited in size. This work establishes a robotic grasping system through physics simulation to collect a multimodal dataset. To address the sim-to-real transfer gap, we propose a migration strategy encompassing domain randomization and domain adaptation techniques. The experimental results demonstrate that the proposed fusion framework achieves markedly enhanced prediction performance (approximately 10%) compared to other baselines. Moreover, our findings suggest that the trained model can be reliably transferred to real robotic systems, indicating its potential to address real-world challenges.Comment: Accepted by IROS 202

Transcriptome analysis reveals unique metabolic features in the Cryptosporidium parvum Oocysts associated with environmental survival and stresses

BACKGROUND: Cryptosporidium parvum is a globally distributed zoonotic parasite and an important opportunistic pathogen in immunocompromised patients. Little is known on the metabolic dynamics of the parasite, and study is hampered by the lack of molecular and genetic tools. Here we report the development of the first Agilent microarray for C. parvum (CpArray15K) that covers all predicted ORFs in the parasite genome. Global transcriptome analysis using CpArray15K coupled with real-time qRT-PCR uncovered a number of unique metabolic features in oocysts, the infectious and environmental stage of the parasite. RESULTS: Oocyst stage parasites were found to be highly active in protein synthesis, based on the high transcript levels of genes associated with ribosome biogenesis, transcription and translation. The proteasome and ubiquitin associated components were also highly active, implying that oocysts might employ protein degradation pathways to recycle amino acids in order to overcome the inability to synthesize amino acids de novo. Energy metabolism in oocysts was featured by the highest level of expression of lactate dehydrogenase (LDH) gene. We also studied parasite responses to UV-irradiation, and observed complex and dynamic regulations of gene expression. Notable changes included increased transcript levels of genes involved in DNA repair and intracellular trafficking. Among the stress-related genes, TCP-1 family members and some thioredoxin-associated genes appear to play more important roles in the recovery of UV-induced damages in the oocysts. Our observations also suggest that UV irradiation of oocysts results in increased activities in cytoskeletal rearrangement and intracellular membrane trafficking. CONCLUSIONS: CpArray15K is the first microarray chip developed for C. parvum, which provides the Cryptosporidium research community a needed tool to study the parasite transcriptome and functional genomics. CpArray15K has been successfully used in profiling the gene expressions in the parasite oocysts as well as their responses to UV-irradiation. These observations shed light on how the parasite oocysts might adapt and respond to the hostile external environment and associated stress such as UV irradiation

A Novel Fast and Robust Binary Affine Invariant Descriptor for Image Matching

As the current binary descriptors have disadvantages of high computational complexity, no affine invariance, and the high false matching rate with viewpoint changes, a new binary affine invariant descriptor, called BAND, is proposed. Different from other descriptors, BAND has an irregular pattern, which is based on local affine invariant region surrounding a feature point, and it has five orientations, which are obtained by LBP effectively. Ultimately, a 256 bits binary string is computed by simple random sampling pattern. Experimental results demonstrate that BAND has a good matching result in the conditions of rotating, image zooming, noising, lighting, and small-scale perspective transformation. It has better matching performance compared with current mainstream descriptors, while it costs less time

Rapid and Visual Detection of Monkey B Virus Based on Recombinase Polymerase Amplification

Monkey B virus (BV) infection in humans and other macaque species has a mortality rate of approximately 80%. Because BV infects humans through bites, scratches, and other injuries inflicted by macaques, the simple and rapid diagnosis of BV in field laboratories is of great importance to protect veterinarians, laboratory researchers, and support personnels from the threat of infection. Two recombinase polymerase amplification (RPA) assays with a closed vertical flow (VF) visualization strip (RPA-VF-UL27 and RPA-VF-US6) were developed that target two conserved genes combined with a one-off, closed visualization strip device. We compared the sensitivities and specificities of the two assays after optimization of the reaction conditions. The performance of RPA-VF-US6 at room temperature was determined to evaluate its potential in point-of-care (POC) testing. RPA-VF-US6 specifically detected the positive plasmid control (rather than nucleic acids of herpesviruses) with a detection limit of 28 copies, while RPA-VF-UL27 had cross-reactivity with HSV-1, but even 3.4 copies of plasmid standards were readout by this assay. Moreover, RPA-VF-US6 had excellent performance at room temperature (the detection limit was 2,800 plasmid copies), indicating the potential of RPA-VF-US6 in POC testing. We developed two RPA assays for BV visualization diagnosis. RPA-VF-US6 is a simple, rapid, and specific detection method for BV. The entire reaction can be performed at a constant temperature within 30 min, suggesting the potential of RPA-VF-US6 for POC testing in field laboratories without sophisticated instruments

Epigenetic control of embryo–uterine crosstalk at peri-implantation

Abstract(#br)Embryo implantation is one of the pivotal steps during mammalian pregnancy, since the quality of embryo implantation determines the outcome of ongoing pregnancy and fetal development. A large number of factors, including transcription factors, signalling transduction components, and lipids, have been shown to be indispensable for embryo implantation. Increasing evidence also suggests the important roles of epigenetic factors in this critical event. This review focuses on recent findings about the involvement of epigenetic regulators during embryo implantation

Alpha-Lipoic Acid Preconditioning and Ischaemic Postconditioning Synergistically Protect Rats from Cerebral Injury Induced by Ischemia and Reperfusion Partly via Inhibition TLR4/MyD88/ NF-κB Signaling Pathway

Background/Aims: A combination of alpha-lipoic acid preconditioning (ALAP) and ischaemic preconditioning (IPC) has not been tested in an in vivo rat cerebral ischaemia/reperfusion injury (I/RI) model, and the potential protective mechanisms have not been well elucidated. The aim of this study was to investigate the role of the TLR4/ MyD88/ NF-κB signaling pathway in the synergistically neuroprotective and anti-inflammatory effects of ALAP and IPC. Methods: One hundred and fifty male Sprague-Dawley rats, weighing 180-230 g, were randomly divided into the following 5 groups: 1) sham-operated control; 2) I/R; 3) I/R+ALAP; 4) I/R+IPC; 5) I/R+IPC+ALAP. After 2 h of reperfusion, the infarct size, neurological deficit scores, brain oedema, oxidative stress, and inflammatory and apoptotic biomarkers were assessed. In addition, reactive oxygen species (ROS) and cell apoptosis were detected by DHE staining and TUNEL staining, respectively. Results: Both ALAP and IPC treatment attenuated the I/RI-induced neuronal injury, reflected by reductions in the infarct size, neurological deficit scores, brain oedema, lactate dehydrogenase (LDH) release and the inflammatory response, as well as decreased HMGB1, TLR4, MyD88, p65, C-Caspase 3 and Bax expression and increased IKB-α, HO-1, SOD-2 and Bcl-2 expression compared to that in the I/R group. Furthermore, the combination of the two strategies had synergistic anti-inflammatory effects and antioxidant benefits, ultimately limiting neuronal apoptosis. Conclusion: The ‘cocktail’ strategy exhibited a significant neuroprotection against I/RI by attenuating neuroinflammation via inhibition of the TLR4/MyD88/NF-κB signaling pathway

Streptococcal Toxic Shock Syndrome Caused by Streptococcus suis Serotype 2

BACKGROUND: Streptococcus suis serotype 2 ( S. suis 2, SS2) is a major zoonotic pathogen that causes only sporadic cases of meningitis and sepsis in humans. Most if not all cases of Streptococcal toxic shock syndrome (STSS) that have been well-documented to date were associated with the non-SS2 group A streptococcus (GAS). However, a recent large-scale outbreak of SS2 in Sichuan Province, China, appeared to be caused by more invasive deep-tissue infection with STSS, characterized by acute high fever, vascular collapse, hypotension, shock, and multiple organ failure. METHODS AND FINDINGS: We investigated this outbreak of SS2 infections in both human and pigs, which took place from July to August, 2005, through clinical observation and laboratory experiments. Clinical and pathological characterization of the human patients revealed the hallmarks of typical STSS, which to date had only been associated with GAS infection. Retrospectively, we found that this outbreak was very similar to an earlier outbreak in Jiangsu Province, China, in 1998. We isolated and analyzed 37 bacterial strains from human specimens and eight from pig specimens of the recent outbreak, as well as three human isolates and two pig isolates from the 1998 outbreak we had kept in our laboratory. The bacterial isolates were examined using light microscopy observation, pig infection experiments, multiplex-PCR assay, as well as restriction fragment length polymorphisms (RFLP) and multiple sequence alignment analyses. Multiple lines of evidence confirmed that highly virulent strains of SS2 were the causative agents of both outbreaks. CONCLUSIONS: We report, to our knowledge for the first time, two outbreaks of STSS caused by SS2, a non-GAS streptococcus. The 2005 outbreak was associated with 38 deaths out of 204 documented human cases; the 1998 outbreak with 14 deaths out of 25 reported human cases. Most of the fatal cases were characterized by STSS; some of them by meningitis or severe septicemia. The molecular mechanisms underlying these human STSS outbreaks in human beings remain unclear and an objective for further study